Is Bipolar Disorder Connected to Major Depression?

Bipolar disorder is a mental health condition that leads to severe mood swings. If you have an identified condition of depression, it cannot "develop into" or "lead to" bipolar disorder.

Bipolar disorder is a mental health condition that leads to severe mood swings. This is usually visible in the form of extreme emotional highs and lows. Sometimes, people can misread the symptoms of bipolar disorder as schizophrenia symptoms. Although bipolar disorder and schizophrenia do have some common attributes, they are two different mental health disorders.

Both bipolar disorder and major depression are classified as mood disorders. Both conditions are challenging. but with proper care, they can be effectively managed.

Bipolar disorder is classified into different types and may include mania, hypomania, or both. The symptoms depend on the type of bipolar disorder but typically cause major changes in your mood and behavior.

Bipolar I disorder

This involves manic incidents that last for a minimum of seven days, along with any hypomanic or major depressive incident. In some bipolar I disorder cases, people may also have depression that lasts for at least two weeks, while in other cases, it may involve incidents of depression along with other manic symptoms. 

Bipolar II disorder

A person with bipolar II disorder has had at least one hypomanic and one major depressive incident but has never had a manic incident.

Cyclothymic disorder

You’re diagnosed as having a cyclothymic bipolar disorder when you’ve had multiple incidents of hypomania symptoms along with periods of depression for at least two years, or in the case of children and teenagers, for one year. 

Other symptoms

Some people with bipolar disorder may have episodes of depression that lead to feelings of sadness, worry, and hopelessness. These phases of depression may also include restlessness, having trouble with sleep, slow speech, forgetfulness, lack of concentration, loss of interest in activities, and suicidal thoughts. 

You may have bipolar disorder even if your symptoms are less severe. For example, some individuals with bipolar II disorder may have hypomanic episodes but may feel that everything is normal, while friends and family notice the considerable changes in the mood and activity levels that suggest bipolar disorder. If people who have frequent hypomanic episodes are not given timely treatment, this may lead to manic episodes or even depression. 

Although mania and hypomania have similar symptoms, they are two separate conditions. Mania, also known as a manic episode, usually lasts for a week or more, during which you may have a sudden change in mannerisms. On the other hand, hypomania does not lead to noticeable changes in normal social and professional functioning and typically lasts for a minimum of four days. 

What characterizes mania is heightened talkative behavior along with a reduced need for sleep, distractibility, rapid thoughts, and accelerated speech. Other signs of manic episodes include impulsive behavior, elevated mood that is subject to rapid mood swings, and irritability. 

If the person who has these symptoms needs to be hospitalized eventually, then the period is regarded as mania rather than hypomania.

Keep in mind that this mania is a naturally occurring state and is different from mania caused by substance use or other medical conditions such as dementia, brain injury, brain tumors, or stroke. If you’ve had just one manic phase or episode, it qualifies as bipolar I disorder. But people with bipolar I disorder usually also have phases of hypomania and depression.

Depression, also known as major depressive disorder, is a medical condition that affects you mentally and physically. Some of the symptoms of depression are:

• Sadness
• Lack of interest in doing things
• Tiredness and lack of energy  
• Disturbed sleep or sleeping a lot
• Inability to think clearly or make decisions
• Feelings of worthlessness
• Sluggish movements and speech patterns, serious enough to be easily noticed by others

You’ll be diagnosed as having depression if these symptoms last for more than two weeks along with a marked change in your actions. Adults who are depressed for more than two years will be classified as having a persistent depressive disorder, whereas, for children, this duration is one year. 

People with this condition typically show other symptoms such as eating too little or too much and having a sense of hopelessness.

Several factors can contribute to depression: 

• Changes in specific chemicals in the brain may lead to symptoms of depression.
• The condition can also run in the family. Research shows that if one identical twin has depression, there is a 70% chance of the other getting it in their lifetime.
• Individuals with low self-esteem or those who quickly get bogged down by stress are more likely to get depressed.
• Consistent exposure to violent situations, neglect, or abuse may increase the risk of depression. 

While depression is considered a “unipolar” (uni-, one) disorder, “bipolar” (bi-, two), as the word suggests, is a condition where you move from one extreme to another. You are either on a high (called a manic phase) or you feel low (called a depressive episode). 

It's estimated that one in three people with bipolar disorder has been misdiagnosed with depression. A study found that around 40% of the individuals who had bipolar disorder were initially diagnosed with depression. An incorrect diagnosis leads to unsuitable treatment that usually includes antidepressants.

When people with bipolar disorder are treated with antidepressants, it can lead to manic episodes. Research on individuals with bipolar disorder found that 55% of all people who were initially diagnosed with depression also showed signs of mania.

Another study found that a delay in prescribing mood stabilizers to those with bipolar disorder led to considerably higher healthcare expenses.

Although some of the symptoms of depression and bipolar disorder may be similar, you should note that there are other critical differences between these two conditions. Since these conditions have several symptoms in common, it’s difficult to make an accurate diagnosis.

If you have an identified condition of depression, it cannot “develop into” or “lead to” bipolar disorder.

But if you have been diagnosed with depression in the past, you may have a type of bipolar disorder with depression as one of the symptoms. It’s important to identify the disorder as soon as possible to make sure you get the right treatment.